1. Field of the Invention
The present invention relates to an electrical connector. More specifically, the present invention relates to a symmetrical electrical connector that can connect with identical copies in which the individual signal lines have minimized crosstalk.
2. Discussion of Background Information
The use of circuit boards is well known in the data processing industry. Multiple circuit boards housed in larger towers need to be connected together to allow the signals to pass from one to the other. One such connector is called a “bowtie connector,” in which both ends of the connector are identical and can connect together orthogonally. Specifically, the male and female pins are separated into four separate quadrants. The signals and grounds are then assigned to specific pin pathways along the wires in the connectors. The pins are organized around an axis of symmetry so that one set of male/female pins is two quadrants that are the mirror image of the opposing set of female/male pins in the opposing two quadrants. Thus, two identical connectors will carry the proper signal if one connector is rotated 90° relative to the other connector.
FIG. 1 shows an example of a signal pin layout on such a bowtie connector 100. The pin layout is separated into four quadrants: top 102, bottom 104, left 106 and right 108 in FIG. 1, in which the top and bottom 102 and 104 include male connectors (“M”) and the left and right 106 and 108 include female connectors (“F”). The diagonal line 110 from the top left to the bottom right defines the axis of symmetry. Thus, if two connectors of the same type are rotated 90°, then the proper male and female connectors will always align and connect.
Male connectors are typically referred to as “pins,” whereas female connectors are referred to as “sockets.” For ease of discussions, the term “pins” herein shall cover both.
The electrical pathways that connect the circuit boards to the pins are typically provided via flexible printed circuit boards, which support pathways on both sides of the flexible printed circuit board. An example of such a flexible printed circuit board 200 is shown in FIG. 2. In general, a single flexible printed circuit board can connect with two columns of pins on the end connector (often referred to as a “header”). In the prior art of FIG. 1, the male and female connectors collectively form fourteen (14) columns, such that seven (7) flexible printed circuit boards can provide connections for all of the pins in the design of FIG. 1. FIG. 3 illustrates which pins align with the various flexible printed circuit boards.
In the prior art design, the assignment of signals and grounds to various pins was driven by mechanical concerns. For example, it was determined that it was conceptually simple to track the signals along the flexible printed circuit boards if the various signal pairs were aligned one after each other on opposite sides of the flexible printed circuit board. As a result, the signal carrying pins are aligned along diagonals parallel with an axis of symmetry.